Ancestral Statue + Kozilek's Unsealing + Primal Vigor

Ancestral Statue

Kozilek's Unsealing

Primal Vigor

How it works

1. Cast Ancestral Statue by paying 4.
2. Kozilek's Unsealing's first ability triggers, creating four 0/1 Eldrazi Spawn creature tokens.
3. When Ancestral Statue enters the battlefield, it triggers, returning itself from the battlefield to your hand.
4. Activate the Eldrazi Spawns by sacrificing them, adding CCCC.
5. Repeat.

This loop is all about setting up a self-sustaining engine where Ancestral Statue continuously pays for its own return trip. As you cast the Statue for four mana, Kozilek's Unsealing triggers because the Statue's mana value hits that sweet spot, outputting two Eldrazi Spawn tokens that Primal Vigor then doubles into a bounty of four. Sacrificing those tokens generates the exact four colorless mana needed to recast the Statue, while the Statue's own entry trigger forces it right back to your hand so you can do it all over again.